Frictionless Reentry

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For any spacecraft which travels through the Earth's atmosphere, there's a critical thing which needs to be considered beforehand. Space travel is fast, and hitting the atmosphere at the kind of speed you'd have in orbit will make your spacecraft hot. Very hot. Atmospheric friction takes the form of a supersonic shockwave as the air can't flow out of the way fast enough and is superheated by the resulting compression. If you attempt to plow through the air without sufficient shielding, disaster could (and indeed, horrifically, did at one point) occur.

It's fairly common for fiction to ignore this little inconvenient fact, because it means characters and impractically designed spaceships can get onto (or off) a planet without burning up. It simply doesn't include an atmosphere. In some cases, Applied Phlebotinum is used (Deflector Shields are a common method for sufficiently advanced sci-fi cultures; shields that can block a nuclear weapon can usually also handle reentry), or the ship simply slows down before reentry to avoid burning up. The latter isn't necessarily too unrealistic for a ship which is using nuclear engines, or otherwise doesn't need to worry about fuel (or balancing fuel consumption with arrival time). If you have enough energy, cooling, and propellant (the latter two are still needed until the air itself becomes dense enough to be useful), you can move as slowly as you want, but "enough" here is really big. The issue for all current orbital spacecraft is that they need to use most of their fuel to lift fuel (not crew or payload) to the altitude where it will be burned, and a ship that used its engines to slow down would be much more expensive since it'd have to carry even more fuel.

Note this trope does not generally apply to anything with Anti Gravity or similar propulsion systems as such craft would be able to hover over a planet instead of needing to orbit a planet. Orbital rings, shells, elevator or anything else in geo-stationary orbit are also generally exempt as there is no need for them to move at hyper velocities to avoid crashing back down onto the planet. Craft that are in the process of taking off may or may not be exempt if they have not yet accelerated to orbital velocities or if they do not gain any horizontal velocity to escape a planet's orbit.

Examples:

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Anime

Averted in Mobile Suit Gundam, given the Real Robot setting of the series. In the first case, Zeon forces don't actually expect the Gundam to be able to make it through reentry...because their own Zakus can't, which is demonstrated by the unlucky pilot Crown and his Zaku melting and shedding parts when he can't make it back to the Musai. The Gundam surprises the Zeon forces by deploying a 'heatproof film' and surviving to make landfall.

Mobile Suit Zeta Gundam also does this to another minor named pilot as a point of character development for Jerid Messa. His friend, Kacricon, had attempted to defeat the Gundam MKII by using Earth's field gravity to his advantage. That didn't go over so well, and with its heat shield is destroyed, his Marasai burned up in the atmosphere.

In the first episode of Mobile Suit Gundam Wing, Heero's Wing Gundam is shown undergoing re-entry heating while approaching Earth. It would make sense that the Gundams built for Operation Meteor would be made to withstand such heating since they were built on the space colonies for the purpose of going to Earth. Also, it was equipped with an outer shell that disguises it as a space shuttle, adding an extra layer of protection.

In Mobile Suit Crossbone Gundam, Kincaid manages to survive reentry using a beam shield rather than a physical one, which nobody was sure was even possible. He is still an inch from death afterward and needs immediate medical attention.

Kira Yamato is forced to try to re-enter in the Aile Strike as he deployed to defend the Archangel and shuttles shortly before their re-entry. His shield melts up before the Archangel (which deploys a similar heatproof film as the White Base) maneuvers to catch it atop one of its legs. This saves Kira from the worst of it, but he's still cooked inside the Strike and suffers for it once they make planet-side. It's made quite clear he would never have survived if he wasn't a genetically-engineered superhuman.

Interestingly, when Kira sends the Freedom Gundam through the atmosphere as part of his Big Damn Heroes/He's Back moment, the Freedom nor Kira suffer from this. It's implied that the Phase Shift Armor that runs through the suit was sufficient enough to survive; the Freedom had the advantage of having near-unlimited energy with its N-Jammer Canceller and a clear-minded Kira at the controls, while the first time Kira went catatonic after the Duel destroyed a civilian shuttle he tried to protect and the Strike is battery powered, thus it wasn't sure how long it could survive.

In Mobile Suit Gundam SEED Astray, Lowe and the Red Frame ends up facing this problem when a fight with the Gold Frame sends him hurtling into the gravity well of Earth. His Junk Guild buddies, however, use their ship and the massive amount of junk they gathered as a shield to grab Lowe and ride it out to Earth. They wreck their ship in the process, though.

The Macross franchise does deal with the friction of re-entry on occasion.

While its re-entry does generate a lot of heat, the YF-19 shows just how far craft have come by the time of Macross Plus, since it not only makes a safe re-entry but does so completely unpowered and spinning uncontrollably while trying to avoid the orbital defense satellites.

In Getter Robo Armageddon, this is averted as the Getter Team and Shin Getter is thought lost when their attempt to destroy Ganymede is foiled and they're launched back to Earth when their own Stoner Sunshine is reflected back at them. They're unable to reright themselves as they enter the atmosphere and it's feared that they've burnt up. Thankfully, Shin Dragon saves the day.

Amusingly, averted in Hellsister Trilogy. Supergirl just ignores the air friction when she streaks into space, but she makes sure of reducing speed before flying back into Earth in order to avoid to damage the planet's atmosphere.

Film

Flight of the Navigator: The ship flies up to the edge of the atmosphere and back down again at multi-Mach speed with no heat or friction effects. Justified because of its advanced technology.

Aliens. The dropship's entry into the atmosphere of LV-426 apparently causes no heat buildup at all.

The Sulaco is a starship, it has enough power and fuel to enter or exit the gravity well at will so it's not limited to orbital velocity. At the time the Cheyenne drops from it, the Sulaco's speed is not stated but it's clearly not so fast that atmospheric entry is a problem for the dropship —in fact, it drops vertically using gravity to accelerate and then fires thrusters to gain additional speed. This clearly implies that the craft was moving significantly slower than orbital velocity, presumably slow enough that atmospheric friction wasn't an issue.

Revenge of the Sith has the "not to worry, we are still flying half the ship" incident, wherein they even have firefighting ships swoop in alongside to put out the fires of reentry before Anakin crash-lands.

Averted in Serenity. The start of the movie shows the titular ship beginning its reentry, including a brief scare for the crew when an apparently important part randomly breaks off The Alleged Starship.

Averted in Gravity, when Dr. Stone flies the Chinese capsule from Tiangong back to Earth. It's far from smooth.

Averted in Guardians of the Galaxy. When Ronan's spaceship enters the atmosphere of a planet, the surface of the ship glows red-hot. It's such a massive ship, however, that its sheer mass allows it to continue with no ill effects.

In Star Trek: Generations, when the saucer section of the Enterprise-D is blown into the planet's gravitational pull by the stardrive section's destruction, you can see the front end of the saucer ignite into flames, but once it enters planetside, there's no visible damage on the front. It's implied that the shields saved it from being destroyed. Doesn't save it from being ravaged once it hits the planet itself.

Zig-zagged in Star Trek Into Darkness. The Enterprise is in freefall after the damage the Vengeance has caused and the ship starts burning up. Sulu even says that, without the shields, they'll burn up — you see panels being torn off as its in freefall. However, the Enterprise ultimately doesn't burn up — it's heavily ravaged from all the shit it went through, but it's still flyable. Even worse, when the Vengeance zips pass mere seconds later, it isn't even harmed at all!

Averted in Star Trek Beyond. When the Enterprise saucer is forced into a minimally controlled entry into a planet's atmosphere, aiming the saucer so it's presenting minimal air resistance, the front of the ship is still charred and it loses a fair amount of hull plating. The drone ships, which are smaller and pursing at full speed, are incinerated.

Literature

Averted in The Night's Dawn Trilogy by Peter F. Hamilton. During an orbital engagement, one of the mercenary starships grazes the atmosphere to destroy the missiles chasing it, as they're designed for deep space (the starship was also designed for space, but was spherical). Even with being relatively aerodynamic, having internal strengthening forcefields, and only using the upper atmosphere, the ship was nearly destroyed.

In X-Wing: Starfighters of Adumar, it's noted that an X-Wing's shields protect it from reentry. Thus, Wedge can maintain a higher speed on his entry to Adumar's atmosphere than the unshielded Blades escorting him can.

During the very first X-Wing book, Corran actually uses a planet's atmosphere to damage a TIE fighter by luring it close enough to the planet during a dogfight to cause reentry heat to begin building up.

Other parts of the SWEU, including some books in the same series, use the friction of atmospheric reentry in various ways. Attaching extra hulls to burn up during the descent lets a squadron of X-Wings disguise itself as part of a meteorite shower, letting them infiltrate a hostile world. In the New Jedi Order, the Wraiths have developed single-person reentry pods with ablation shielding for basically the same purpose.

In Han Solo at Star's End, the Millennium Falcon uses its shields to offset the heat of entering the atmosphere of Duroon.

An aversion in Before the Storm leads to a Red Shirt moment. During a military exercise a fleet tender drops out of hyperspace too late to decelerate and is lost with all hands when it hits a planet's atmosphere.

The Corellia trilogy sees a New Republic Intel agent crashing her ship on Corellia, noting as she does so that most ships are designed to survive the heat of a ballistic re-entry - but only once. They're intended to have functional engines to slow them down before they hit the atmosphere.

Averted in Use of Weapons. When a Culture module wants to make a swift getaway from a planet's surface, it displaces (teleports) away the air in front of it to behind it as fast as it's moving. It thus makes a multi-mach trip to orbit through a nice, frictionless, self-created vacuum. Of course, The Culture are Sufficiently Advanced Aliens.

Averted in Animorphs. The prologue to The Alien shows how Ax wound up on Earth, including an automated reentry by the dome of the Dome Ship GalaxyTree complete with glow from ram pressure. Meanwhile The Andalite Chronicles includes a hypersonic chase through the atmosphere of the Taxxon homeworld, with the ships involved becoming basically self-propelled meteors. Late in the chase, a Bug fighter randomly explodes in midair because its shields failed.

Averted in Starship Troopers. The drop pods for infantry have several layers, the first few of which are meant to deal with the friction of being dropped into atmosphere. Johnny is well aware of what could happen if they fail.

An inversion happens in Invasion of Kzarch; where the marine platoon preforms a hot drop even though they could've come in slow. The thing is, they needed to avoid getting shot at, so...

Averted in the Doctor Who story "Voyage of the Damned": The Titanic is glowing when crashing to Earth; however, this is no longer visible when it nearly (or in "Turn Left", actually) hits Buckingham Palace. The Doctor even uses the friction of re-entry to reignite the Titanic's engines.

In the Star Trek: The Next Generation episode "The Arsenal of Freedom", this is averted when Geordi uses the friction from atmospheric reentry to expose a cloaked drone harassing the Enterprise.

In Star Trek: Voyager, Voyager is able to land on planets without this ever being a problem. Averted in the "Equinox" two-parter, when the captain of the Equinox directs his ship into the atmosphere of a planet, knowing it would tax his shields. Voyager follows, suffering the same, only they are also being harassed by extra-dimensional aliens constantly assaulting their shields, so Janeway has to give up before the shields fail.

If reentry is actually shown in the Stargate-verse, the trope is usually averted.

This is used to the heroes' advantage in the episodes "Nemesis" and "Enemies", when they scuttle the Asgard vessel overrun with Replicators by disabling the shields and performing an uncontrolled re-entry. It should be noted that doing this requires the assistance of Thor (telling them exactly where to place all of the charges to both disable the engines that control reentry and to disable the shields).

Averted with a vengeance in "Enemies", where Apophis is killed on board a Ha'tak full of replicators by disabling the engines used to decelerate after leaving hyperspace, disabling the shields, and letting it crash into a planet (after SG-1 safely evacuates of course).

It's used to their disadvantage in "Last Stand", where the enemy tracks Jacob & Daniel's cloaked ship by the heat of its reentry.

In Stargate Atlantis, the episode "Lifeline" has McKay explains that even with the ZPM powering the shields, too steep a descent during atmospheric re-entry could overtax it and cause the shield to fail, while even with it in place, the incredible turbulence could cause the city to break into a million pieces long before it crashes into the surface.

Inverted in Battlestar Galactica (2003), where we get to see The Galactica dropping through the atmosphere like a giant superheated rock in one episode as part of an Airstrike Impossible. Galactica wasn't moving anywhere near fast enough for reentry friction, and Vipers were able to leave Galactica without themselves experiencing reentry friction.

Generally averted. Entering the atmosphere is described as a fairly rough and sometimes dangerous act for the Serenity, though the latter is more due to her state of disrepair than the actual heat of reentry. Wash's talent for piloting and Kaylee's talent for rapidly jury-rigging repairs for failing systems are able to compensate for Mal's lack of talent for making enough money to properly maintain his ship.

In the pilot, we see a Reaver ship maneuvering to present its presumably better-shielded side to atmo, and the ship being surrounded by white-hot plasma. Shown Their Work, indeed.

Averted on Babylon 5, particularly in the season 3 finale, when Sheridan commanded the White Star to dive out of orbit into the Shadow capital and detonate two 500 megaton warheads.

Tabletop Games

You wouldn't normally expect scientific accuracy from Warhammer 40,000, but Space Marine Drop Pods do have to have heat shielding and stabilizer systems to survive reentry.

Although played straight with most of the other vehicles, which look about as aerodynamic and shielded as a block of candyfloss and which somehow manage to be SSTO spaceplanes and floating cathedrals. Semi-justified given the advanced materials used in their construction, and because there seems to be one school of thought in Imperial engineering and that thought is "Thrussssssssssssssst!!!".

To be fair, all these flying cathedrals were never intended to actually enter atmosphere. They have shuttles and drop pods for that.

Video Games

A stock ending for Sonic the Hedgehog games is for Sonic to fall to the planet after blowing up a space station. Sonic 2 shows Sonic actually fly to space on the outside of a ship. Sonic Adventure 2 partly corrects the astronomy by making it possible for characters to die if they hit the atmosphere (Eggman even uses it in an attempt to eliminate Sonic). However, the atmosphere's height varies according to how high the platforms above it are.

Not really. All that changes is how long until your character appears to enter the atmosphere- and it has to do with how many platforms are below you, in order to give you a chance to return to a lower part of the stage.

That being said, there has been no case in the entire series of an organic character falling from the upper atmosphere to the troposphere without being in a vehicle designed for it or tapping into the reality-warping power of the Chaos Emeralds to protect them. It seems ascending is just fine in the Sonic games, but descending is always lethal. The endings of Sonic 3 & Knuckles and Sonic Advance even show the invulnerable, non-breathing Super Sonic and whatever objects he's carrying encounter some atmospheric friction as he's falling back down.

Averted in Mass Effect 2, in which Shepard is quite badly killed by reentry by him/herself in a space suitnote Subsequent video footage of the Lazarus project shows that Shepard had broken every single bone in multiple places, and suffered massive organ failure due to, well, death. Interestingly, the hard part of resurrecting Shepard isn't fixing the physical damage, but rather cataloguing the mental damage and finding a way to reverse it without significant alterations. Of course, the space suit ensured s/he was intact enough to be rebuilt...

Amusingly averted in Mario Kart Wii, where falling off Rainbow Road will result in your character lighting up as they plummet towards the earth, and they'll be smoking when Lakitu returns them to the track.

Averted in Freelancer. Planets have docking rings to guide them safely to the surface and any ship attempting direct entry to a planet will flare up and eventually be destroyed. Of course, it is also an example of Gameplay and Story Integration.

Zig-Zagged in Star Trek: Bridge Commander. Moving too close to a planet will cause an orange, fiery halo to appear around your shields - even if your shields are down - until you splat into the planet. No matter how fast you're travelling, though, you'll never burn up or suffer damage unless you actually hit the planet. Given that planets in this sector are about 200km in diameter, they don't have very thick atmospheres.

Averted in Star Trek: Klingon Academy. Although flying slowly through a planet's atmosphere provides good camouflage, plowing ahead in your Bird of Prey at high impulse without shields is an excellent way to become a meteor and fail your mission.

Halo averts it. Drop Pods and escape pods burn up on re-entry as one would expect, while Pelicans don't reenter fast enough to start heating up.

Frontier: First Encounters got it averted, in that a manual landing requires to keep an eye on approach velocity and either your ship has Atmospheric Shielding installed (and it's tough enough to work as armor) or the next reentry will end rather prematurely and spectacularly.

Averted in the X-Universe series. Any planets shown aren't backdrops, but actual physical objects with atmospheres, and you can reach them in a ship provided they're not on the opposite side of the Invisible Wall surrounding the sector. (It usually takes forever, though.) Like Freelancer above, objects in the X series aren't designed for atmospheric flight and will burn up. The planet in the sector Split Fire in X3: Terran Conflict has gotten notoriety for this, since its atmosphere starts about a kilometer behind one of the jumpgates, which is normally prime real estate for player-owned factories.

Averted in Kerbal Space Program as of version 1.0, which adds heating to the previously present slowdown effects of drag, necessitating heat shields to prevent burning up on re-entry. Note that the same effects can be achieved by any high-speed atmospheric travel, not just re-entry. As with everything, the effects of re-entry is downplayed in the game: as long as you have a heat shield, it's safe to re-enter the atmosphere (unless you re-enter so steep that you can't slow down enough to be safe to deploy the parachutes until you hit the ground), even if you are somewhat off-angle.

Of course, there is a Game Mod for that if you're more interested in realism.

Averted in Asura's Wrath. The main characters first death was by atmoshperic reentry. It happens to him again later but survives this time.

Surprisingly, Orbiter plays this halfway straight, despite being very realistic in most respects. There's friction on reentry (enough to bounce you back out of the atmosphere if you enter at the wrong angle) and a visual effect to show heating, but it's impossible to destroy a ship this way. A few modded vehicles avert this trope.

Averted in Xenosaga. At the end of Disc 1, the protagonists enters the atmosphere of a planet on what is essentially a glorified cruise liner. It takes the hidden powers of two of the cast to successfully protect the ship from the heat of reentry. Arguably played with, as some dialogue indicates the ship may have been fine had it entered the atmosphere under more orderly circumstances.

Webcomics

Averted in Starslip when a recurring antagonist gets blown out an airlock by Vanderbeam, who was sick of the antagonist's recurrences: [1]

Most HSD spaceships in Rank Amateur are designed to be aerodynamic so they can aerobrake without getting damaged. Human/Earth Authority ships are either designed either with landing capability or to never enter atmospheres. The latter type would burn up on atmospheric entry.

Western Animation

Futurama, unusually for a comedy series, pays attention to the heat issue: When Bender the robot falls to Earth from space, he's hot enough to instantly melt snow several meters away. (His heat resistance was justified in a later episode - for whatever reason, his designers used a dolomite alloy with very high temperature tolerances.)

The less said about the Professor's wooden spaceship that takes the Castaways to Gilligan's Planet the better.

Averted in the ''Cars Toon'' "Moon Mater", which is about Mater becoming a moon rover as part of a moon mission to rescue an "autonaut" named Impala XIII, who was trapped inside a crater on the Moon. On the way back to Earth, Mater (while narrating) actually adds his friend Lightning McQueen into his story, since McQueen thinks that Mater is making things up. Lightning McQueen is portrayed here as a reentry probe, and as he is heading back toward Earth, his body starts to heat up rapidly because of friction, and as a result he start screaming "Ow! Hot! Hot! Hot! Hot! Hot!" before finally landing in the ocean and sighing in relief.

Real Life

Generally, this trope is averted in Real Life for spacecraft, since objects moving at orbital speeds move fast enough that when they re-enter the atmosphere, friction with Earth's atmosphere heats their hull significantly (a Truth in Television example of Friction Burn). However, objects can drop from a significant height without burning up if they're not moving at orbital speeds. The Red Bull Stratos space diving stunt had an astronaut jump from a helium balloon 39 KM from the surface of the Earth. While this arguably isn't re-entry from space, it's re-entry from the stratosphere into the troposphere, which didn't cause the astronaut to burst into flames.

Contrary to popular belief, Friction contributes a relatively little amount of heat to reentry. The majority of the heat generated is actually from atmospheric compression, the spacecraft is moving so fast that the air in front of it can't get out of the way fast enough, so it gets squeezed, and when you squeeze a gas, you increase its temperature. Most spacecraft do this on purpose, as it's the easiest and cheapest way to slow the craft down enough that it doesn't vaporize on contact with the surface of the planet.

Someone falling from very Low Earth Orbit (but relatively stationary in respect to the surface below, so they fall almost straight down) would hit a maximum speed of 800 miles an hour and then begin slowing due to air resistance, a speed that an aircraft or even a spacesuit with modern materials would have no problem dealing with in terms of frictional heating. The main problem with the idea of orbital height skydiving is that it's easy for the friction at such high speeds to induce a spin or tumble which could cause the diver to black out or be injured or killed due to the g-forces involved. Some kind of drogue parachute, however, which could stabilize the skydiver and slow them down slightly, is entirely feasible.

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